If we simply mandated that everyone install an app on their phone so that the government can track them scales very well. The people without the app would probably be criminals,

Spying on the American public shouldn't be cheap or efficient. We shouldn't abandon our freedom to make the fearful feel better.

More and more, yes. This was in June: https://www.supremecourt.gov/opinions/25pdf/25-112_0am4.pdf

By my understanding, this would be similar to the situation with marketing calls. In the US is it legal for a human to call anyone and market to them. But due to issues from scale, it is illegal for either a program to make the call, or a prerecorded message to be played.

To me, that is precedent in US law that computerized methods of executing human tasks do not fall under the same rules.

There hasn't been an explicit ruling from the supreme Court that applies here, but there are indications that they would have ruled that the fourth amendment applied. They've explicitly avoided closing the door on that possibility.

https://en.wikipedia.org/wiki/United_States_v.Jones(2012)

> Also left unanswered was the broader question surrounding the privacy implications of a warrantless use of GPS data without a physical intrusion – as might occur, for example, with the electronic collection of GPS data from wireless service providers or factory-installed vehicle tracking and navigation services.[27] The Court left these matters to be decided in some future case, saying, "It may be that achieving the same result through electronic means, without an accompanying trespass, is an unconstitutional invasion of privacy, but the present case does not require us to answer that question."

https://en.wikipedia.org/wiki/Carpenter_v._United_States

> Ultimately, in Carpenter the court determined that the third-party doctrine could not be extended to historical cell site location information (CSLI). Instead, the Court compared "detailed, encyclopedic, and effortlessly compiled" CSLI records to the GPS information at issue in United States v. Jones, recognizing that both forms of data accord the government the ability to track individuals' past movements.[24] Furthermore, the Court noted that CSLI could pose even greater privacy risks than GPS data, as the prevalence of cellphones could accord the government "near perfect surveillance" of an individual's movements. Accordingly, the Court ruled that, under the Fourth Amendment, the government must obtain a search warrant in order to access historical CSLI records.[1]

Of course there are no guarantees on how they'd rule today, but in the past they've ruled that scale and ease of access and compilation are significant enough to mean that fourth amendment protections should apply.

It's not about many people vs. few people. It's about a single person doing little with a lot of effort vs. a single person doing an enormous amount with minimal effort.

SCOTUS has (sort of) done this in the recent Chatrie case. https://www.supremecourt.gov/opinions/25pdf/25-112_0am4.pdf

It's obviously different in that Chatrie was about google location data, and there actually was a warrant. SCOTUS ruled that warrant was too broad since it captured everyone in that location, not a specific person(s).

Constitutional scholars have pointed out the ALPR are next in line to face challenges based on the same principles as Chatrie - LEO can get a warrant for a specific person(s) to search but cannot search the entire universe.

That would not prevent ALPRs from existing, but it would require a warrant to search them. Which seems reasonable and completely in line with the 4th amendment.

Edit: words/spelling

You don’t need to do that, actually. The legal system in the United States is highly capable of sussing out descriptions like “undue or unreasonable”.

You don’t need to rigidly define scale to demonstrate at a common sense level that there is a major difference between a couple cops writing down your license plate and a nationwide network of them entering your plate into a searchable ledger.

The point at which we decide it's dangerous to the safety, freedom, and happiness of citizens. Every law we have is a balance between "provides good" and "imposes bad" - and we have to adjust where that balance lies on an ongoing basis as things (technology) change.

It’s impossible to “rigidly” define words like “chair” when faced with someone who’s committed to demonstrating ways you’ve failed to do it.

Luckily we never need to do that with words for them to be useful, even in legal contexts.

How many man hours could the department in question realistically dedicate to the investigation without the technology

Scale does matter. Take bacterial infections for example, there's a tipping of scale on the way to full blown sepsis

> Nobody wants to limit the police's ability to investigate crimes.

This is not true of privacy advocates, they do want to limit the ability to fish for circumstantial evidence that targets innocent people and causes suspicion.